Benzene reduction in gasoline by alkylation with higher olefins

ABSTRACT

A benzene-rich gasoline stream is alkylated with higher olefins in contact with a fluid bed of shape selective zeolite catalyst to produce a gasoline product stream reduced in benzene content wherein the high octane value alkylaromatics formed by benzene alkylation are of low carbon number, essentially C10-. Concurrently, a portion of olefins in the gasoline stream are converted to gasoline boiling range hydrocarbons and the sulfur content of the gasoline feedstream is lowered. Besides enhancing the octane value of the feedstream, the process results in a lower Reid vapor pressure and lower sulfur content.

This is a continuation of application Ser. No. 08/028,058, filed Mar. 8,1993, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to a process for the production of a moreenvironmentally suitable gasoline by removing a substantial portion ofbenzene in gasoline by alkylation with C₅ + olefins wherein thealkylated aromatic product unexpectedly comprises essentially C₁₀ -aromatics. Reid vapor pressure (RVP) is reduced and sulfur content islowered.

The record of the development of environmental regulations at theFederal and State levels for the control of emissions from motorvehicles has moved from an early emphasis on end use control, as in therequired application of catalytic converters to motor vehicles andstandards on fleet fuel consumption, to a greater emphasis on changes infuel composition. The first changes eliminated lead based octaneenhancing additives in gasoline. More recently, compositional changes togasoline dictated by environmental considerations include the reductionof low boiling hydrocarbon components, reduction in benzene content ofgasoline and a requirement to substantially increase the oxygen contentof formulated gasoline. Further regulations can be expected in thefuture, probably including regulations stipulating a reduction in theASTM Distillation End Point of gasoline. The sum of the required changesto date presents an unprecedented technological challenge to thepetroleum industry to meet these requirements in a timely manner with aproduct that maintains high octane value and is economically acceptablein the marketplace.

Gasolines manufactured to contain a higher concentration of aromaticssuch as benzene, toluene and xylenes (BTX) can adequately meet theoctane requirements of the marketplace for a high octane fuel.Aromatics, particularly benzene, are commonly produced in refineryprocesses such as catalytic reforming which have been a part of theconventional refinery complex for many years. However, theirsubstitution for the environmentally unsuitable lead-based octaneenhancers is complicated by environmental problems of their own.Environmental and health related studies have raised serious questionsregarding the human health effects of benzene. The findings suggest thatexposure to high levels of benzene should be avoided with the resultthat benzene concentration in gasoline to enhance octane number islimited and controlled to a relatively low value.

When hydrocarbons boiling in the gasoline boiling range are reformed inthe presence of a hydrogenation-dehydrogenation catalyst, a number ofreactions take place which include dehydrogenation of naphthenes to formaromatics, dehydrocyclization of paraffins to form aromatics,isomerization reactions and hydrocracking reactions. The composition ofthe reformer effluent or reformate is shifted toward higher octane valueproduct. Catalytic reforming primarily increases the octane of motorgasoline by aromatics formation but without increasing the yield ofgasoline.

Reformates can be prepared by conventional techniques by contacting anysuitable material such as a naphtha charge material boiling in the rangeof C₅ or C₆ up to about 380° F. (193° C.) with hydrogen in contact withany conventional reforming catalyst. Typical reforming operatingconditions include temperatures in the range from about 800° F. (427°C.) to about 1000° F. (538° C.), preferably from about 890° (477° C.) upto about 980° F. (527° C.), liquid hourly space velocity in the range offrom about 0.1 to about 10, preferably from about 0.5 to about 5; apressure in the range from about atmospheric up to about 700 psig (4900kPa) and higher, preferably from about 100 (700 kPa) to about 600 psig(4200 Kpa); and a hydrogen-hydrocarbon ratio in the charge in the rangefrom about 0.5 to about 20 and preferably from about 1 to about 10.

The treatment of a reformate with crystalline aluminosilcate zeolites isknown in the art and has included both physical treatments such asselective adsorption, as well as chemical treatments such as selectiveconversion thereof. In U.S. Pat. No. 3,770,614 to Graven a processcombination is described for upgrading naphtha boiling rangehydrocarbons by a combination of catalytic reforming and selectiveconversion of paraffinic components to enhance yield of aromatichydrocarbons by contact with crystalline aluminosilicate catalyst havingparticular conversion characteristics. In U.S. Pat. No. 3,649,520 toGraven a process is described for the production of lead free gasolineby an integrated process of reforming, aromatics recovery andisomerization including C₆ hydrocarbons upgrading to higher octaneproduct for blending.

U.S. Pat. No. 3,767,568 to Chen, incorporated herein by reference,discloses a process for upgrading reformates and reformer effluents bycontacting them with specific zeolite catalysts so as to sorb methylparaffins at conversion conditions and alkylate a portion of aromaticrings contained in the reformates.

Recently, a process has been developed to overcome some of the foregoingchallenges in the reformulation of gasoline. The process is known in theart as the Mobil Benzene Reduction (MBR) process and is closely relatedto the Mobil Olefins to Gasoline (MOG) process. The MBR and MOGprocesses are described in U.S. Pat. Nos. 4,827,069 to Kushnerick,4,950,387 and 4,992,607 to Harandi, and 4,746,762 to Avidan, all ofcommon assignee. These patents are incorporated herein by reference.

The MBR process is a fluid bed process which uses shape selective,metallosilicate catalyst particles, preferably ZSM-5, to convert benzeneto alkylaromatics using olefins from sources such a FCC or coker fuelgas, excess LPG, light FCC naphtha or the like. Benzene is converted,and light olefin is also upgraded to gasoline concurrent with anincrease in octane value. Conversion of light FCC naphtha olefins alsoleads to substantial reduction of gasoline olefin content and vaporpressure. The yield-octane uplift of MBR makes it one of the fewgasoline reformulation processes that is actually economicallybeneficial in petroleum refining.

The MBR process as practiced heretofore has relied upon light olefin asalkylating agent for benzene to produce alkylaromatic, principally inthe C₇ -C₉ range. However, some refineries have a surplus of highercarbon number olefins, i.e., C₅ + olefins, and it would be a benefit tothe refiner if these olefins could be used in processes such as MBR.However, alkylation of benzene with such higher olefins would typicallybe expected to produce a sharp increase in the yield of alkylaromaticsof C₁₁ carbon number and above as both mono and polyalkylated aromatics.This is not a preferred mode of operation or gasoline composition.

It is an object of the present invention to provide a process to lowerthe benzene content of gasoline while enhancing octane value byalkylation of benzene in a gasoline feedstock with higher carbon numberolefins without substantially increasing the amount of high carbonnumber alkylaromatics in the product gasoline.

A further object of the invention is to provide the foregoing improvedgasoline with a lower Reid vapor pressure and sulfur content.

SUMMARY OF THE INVENTION

The discovery has been made that a benzene-rich gasoline stream can bealkylated with higher olefins in contact with a fluid bed of shapeselective zeolite catalyst to produce a gasoline product stream reducedin benzene content wherein the high octane value alkylaromatics formedby benzene alkylation are of low carbon number, essentially C10-.Concurrently during the alkylation reaction, a portion of olefins in thegasoline stream are converted to gasoline boiling range hydrocarbons andthe sulfur content of the gasoline feedstream is lowered. Besidesenhancing the octane value of the feedstream, the process results in alower Reid vapor pressure.

A particularly surprising element of the invention is the production ofsubstantially all C₁₀ - alkylaromatics when benzene-rich gasoline isalkylated with C₅ + olefins according to the process of the invention.Ordinarily, alkylation of benzene with C₅ + olefins would be expected toproduce a large quantity of C₁₁ + alkylaromatics by mono or polyalkylation with olefins. The novel chemistry of the instant processunexpectedly avoids the formation of such higher alkylaromatics leadingto the formation of a high octane value gasoline product predominantlyin the C₅ -C₉ range.

More specifically, a fluid bed process for alkylating a benzene-richgasoline boiling range hydrocarbon stream with a hydrocarbon streamcomprising C₅ + olefins to produce gasoline having a reduced benzenecontent and containing aromatics comprising substantially C₁₀ -alkylated aromatics has been discovered. The process comprisescontacting the benzene-rich stream and the C₅ + olefin stream withsolid, shape selective aluminosilicate catalyst particles in a fluidizedcatalyst bed under benzene alkylation conditions whereby an effluentstream is produced comprising gasoline having a reduced benzene contentand containing aromatics comprising substantially C₁₀ - alkylatedaromatics.

A particular embodiment includes a process for the reduction of thebenzene and olefin content of C₅ + FCC gasoline feedstream containingbenzene and C₅ + olefins. The process comprises contacting the C₅ + FCCgasoline feedstream with solid, shape selective aluminosilicate catalystparticles in a fluidized catalyst bed under benzene alkylationconditions whereby the benzene in the feedstream is alkylated with theC₅ + olefins of the feedstream to produce an effluent stream comprisingsaid gasoline having a reduced benzene and olefin content in which thearomatics which are present are substantially entirely C₁₀ - alkylatedaromatics.

The invention encompasses an improvement in the process for reducing thebenzene content of reformate comprising alkylating a reformatefeedstream with light olefins in contact with metallosilicate catalystparticles. The specific improvement embodies alkylating the reformatefeedstream with a C₅ or C₅ + olefin rich feedstream whereby an effluentstream is produced comprising reformate having a reduced benzene contentand containing aromatics comprising substantially C₁₀ - alkylatedaromatics.

DETAIL DESCRIPTION OF THE INVENTION

The present invention comprises an improvement to the Mobil BenzeneReduction process (MBR) generally described herein before and in thecited U.S. patents incorporated by reference. The invention provides aprocess for lowering the benzene content, olefin content, Reid vaporpressure and sulfur content of any benzene-rich C₅ + gasoline boilingrange hydrocarbon feedstream while enhancing octane value. While theseachievements are basic endowments of the MBR process when alkylation ofbenzene is carried out with light olefins, the present inventionembodies the discovery that higher olefins, i.e., C₅ +, can be used asalkylating agents in the MBR process without substantially increasingthe production of higher, i.e., C₁₀ +, alkylaromatics. In a preferredembodiment the invention provides a process integrated into the reformersection of a refinery for the manufacture of high octane gasoline. Theinvention can improve the economics of meeting the benzene specificationof the gasoline pool, preferably reducing the pool benzene content below1% or 0.8%.

One embodiment of the process of this invention resides in theconversion of a portion of a reformate or reformer effluent, or anybenzene-rich C₅ + gasoline feedstream, following fractionation in afractionation system. Portions subjected to conversion in the processare the C₆ fraction; also, the C₆ fraction plus at least a portion ofthe C₉ + or C₁₀ + fraction of the reformate containing aromatic andnon-aromatic compounds. The conversion is carried out at conversionconditions with or without added hydrogen over a shape selectivemetallosilicate catalyst, preferably aluminosilicate.

Reformates or reformer effluents which are composed substantially ofparaffinic and aromatic constituents can be prepared according toconventional techniques by contacting any suitable material such asnaphtha charge material or heavy straight run gasoline boiling in therange of C₅ and preferably in the range of C₆ up to about 400° F. (204°C.) and higher with hydrogen at least initially in contact with anyreforming catalyst. This is a conventional reforming operation whichinvolves a net production of hydrogen and is well known to those skilledin the art as described in Chapter 6 of Petroleum Refining by James H.Gray and Glenn E. Handwerk as Published by Marcel Dekker, Inc. (1984).

Reforming catalysts in general contain platinum supported on an aluminaor silica-aluminum base. Preferably, rhenium is combined with platinumto form a more stable catalyst which permits operation at lowerpressures. It is considered that platinum serves as a catalytic site forhydrogenation and dehydrogenation reactions and chlorinated aluminaprovides an acid site for isomerization, cyclization, and hydrocrackingreactions. Some impurities in the feed such as hydrogen sulfide, ammoniaand organic nitrogen and sulfur compounds will deactivate the catalyst.Accordingly, feed pretreating in the form of hydrotreating is usuallyemployed to remove these materials. Typically, feedstock and reformingproducts or reformate have the following analysis:

                  TABLE 1                                                         ______________________________________                                        COMPONENT (vol %) FEED    PRODUCT                                             ______________________________________                                        Paraffins         45-55   30-50                                               Olefins           0-2     0                                                   Naphthenes        30-40    5-10                                               Aromatics          5-10   45-60                                               ______________________________________                                    

Reforming operating conditions include temperatures in the range of fromabout 800° F. (427° C.) to about 1000° F. (538° C.), preferably fromabout 890° (477° C.) up to about 980° F. (527° C.), liquid hourly spacevelocity in the range from about 0.1 to about 10, preferably from about0.5 to about 5; a pressure in the range of from about atmospheric up toabout 700 psig (4900 Kpa) and higher, preferably from about 100 (700kPa) to about 600 psig (4200 Kpa); and a hydrogen-hydrocarbon ratio inthe charge in the range from about 0.5 to about 20 and preferably fromabout 1 to about 10.

One aspect of the present invention is the incorporation of a processstep comprising the fractionation of the reformate or reformer effluent,or C₅ + hydrocarbon feedstream. The fractionation step permitsseparation of the reformer effluent into several streams or fractions.These streams include a C₆ hydrocarbon fraction rich in benzene; also afraction consisting of C₆ + and a portion of C₉ + aromatic richhydrocarbons. These latter streams contain components of reformate thatcompromise the environmental acceptability of that product. It has beendiscovered in the present invention that all or a portion of thesestreams can be coprocessed by the MBR process in a fluid bed conversionzone containing shape selective aluminosilicate catalyst particles toupgrade these components to environmentally acceptable and high octanevalue gasoline constituents.

As noted earlier, any benzene-rich C₅ + gasoline boiling rangehydrocarbon feedstream can be used in the MBR process, conventionallywith a light olefins feedstream as alkylating agent. However, reformateis preferred. Benzene alkylation processes to reduce gasoline benzenecontent use light olefinic gas feedstocks containing ethene, propyleneor butenes as the alkylating agent. Refinery olefinic streams typicallyinclude FCC offgas, fuel gas, and LPG. The reaction takes place overappropriate catalysts to produce alkyl aromatic hydrocarbons and improvegasoline octane and yield.

C₅ + olefins, it has been found, are also effective alkylating agentswhen used in conjunction with shape selective zeolite such as ZSM-5catalysts in the Mobil Benzene Reduction (MBR) process. The alkylatedaromatic products remain essentially C₁₀ - aromatics. A number ofsources of cracked gasoline streams in the refinery can be used asalkylating agent, including fluid catalytic cracking (FCC) gasoline orThermafor catalytic cracking (TCC) gasoline, coker gasoline, andpyrolysis gasoline. Preferably, a light naphtha stream is used tomaximize the olefin content of the stream as olefins tend to concentratein the C₅ -C₇ hydrocarbon range. Use of cracked gasoline feeds (i.e.,C₅ + olefins) in other benzene alkylation processes will lead toformation of C₁₁ + aromatics. Also, other processes are more susceptibleto catalyst poisoning which would be accelerated in the presence ofnaphtha feeds.

While not wanting to be bound by a theory of operation, it appears thatin the present invention when the benzene-rich stream is coprocessedwith C₅ + olefins over shape selective zeolite catalyst particlesseveral reactions occur that lead to a substantial reduction in thebenzene content of the product of the process and, simultaneously, areduction in the Reid vapor pressure and sulfur content. Thesereactions, it is believed, include cracking, alkylation, andtransalkylation. The C₉ + fraction containing aromatic and non-aromaticcompounds, such as dialkylated aromatics, can enter into transalkylationreactions with benzene under the conditions of the process leading tothe formation of C₇ -C₈ alkylated aromatics from benzene. Also, crackingparaffins, particularly higher molecular weight normal and slightlybranched paraffins, results in the production of compounds that areeffective in alkylating benzene and further producing alkylatedaromatics under the conditions of the conversion process.

Conversion of a benzene-rich gasoline feedstream used in the presentinvention in contact with metallosilicate catalyst particles isgenerally carried out at a temperature between 500° F. (260° C.) andabout 1000° F. (538° C.) preferably between 550°-900° F. (288°-482° C.)and most preferably between 700°-850° F. (371°-454° C.). The pressure isgenerally between about 50 (350 Kpa) and 3000 psig (21000 kPa),preferably between 50-400 psig (350-2860 kPa). The liquid hourly spacevelocity, i.e., the liquid volume of hydrocarbon per hour per volume ofcatalyst is between 0.1 and 250, preferably between 1 and 100. A mostpreferable weight hourly space velocity based on total feed is between0.5 and 3 WHSV. If hydrogen is charged, the molar ratio of hydrogen tohydrocarbon charged can be as high as 10 but it is preferably zero. Anytype of catalytic reactor can be used in the process of the inventionincluding fluid bed, fixed bed, riser reactor, moving bed, and the like.However, the dense phase turbulent fluid bed catalytic reactor ispreferred.

The preferred catalysts are the intermediate pore size zeolites, ofwhich ZSM-5 is the most favored. This zeolite is usually synthesizedwith Bronsted acid active sites by incorporating a tetrahedrallycoordinated metal, such Al, Ga, or Fe, within the zeolitic framework.The ZSM-5 crystalline structure is readily recognized by its X-raydiffraction pattern, which is described in U.S. Pat. No. 3,702,866(Argauer, et al.), incorporated by reference. The medium pore zeolitesare favored for acid catalysis; however, the advantages of these zeolitematerials may be utilized by employing highly siliceous materials orcrystalline metallosilicate having one or more tetrahedral specieshaving varying degrees of acidity.

The preferred catalysts for use in the conversion step of the presentinvention include the medium pore crystalline aluminosilicate zeoliteshaving a silica to alumina ratio of at least 12, and constraint index ofabout 1 to 12. Representative of the zeolites of this type are ZSM-5,ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, MCM-22, and ZSM-48.

Other acidic materials which may be used include MCM-36 (described inU.S. Ser. Nos. 07/811,360 and 07/878,277) and MCM-49 (described in U.S.applications Ser. Nos. 07/802,938 and 07/987,850).

Representative of the larger pore zeolites (constraint index no greaterthan 2), which are useful as catalysts in the process of this invention,are zeolite Beta, TEA mordenite zeolite Y, especially USY and ZSM-12.

Zeolite Beta is described in U.S. Pat. No. Re. 28,341 (of original U.S.Pat. No. 3,308,069), to which reference is made for details of thiscatalyst.

Zeolite ZSM-12 is described in U.S. Pat. No. 3,832,449, to whichreference is made for the details of this catalyst.

The method by which Constraint Index is determined is described fully inU.S. Pat. No. 4,016,218, to which reference is made for details of themethod.

The preferred catalyst for use in the present invention is acidic ZSM-5having an equilibrium alpha value less than 100, preferably less than50. Alpha value, or alpha number, is a measure of zeolite acidicfunctionality and is more fully described together with details of itsmeasurement in U.S. Pat. No. 4,016,218, J. Catalysis, 6, pp. 278-287(1966) and J. Catalysis, 61, pp. 390-396 (1980).

A series of bench-scale pilot unit experiments (Examples 1-5 asdescribed herein) were conducted which showed effective benzenereduction using heavier olefins as the alkylating agent. Two differentcracked stocks were evaluated: a) light (215° F.) FCC gasoline and b)full range pyrolysis gasoline. Feedstock properties for these are givenin Tables 3 and 4, respectively. These cracked gasolines were blendedwith benzene-rich reformate cuts in various proportions and charged to afluid bed reactor containing acidic ZSM-5 catalyst. Operating conditionswere as follows:

                  TABLE 2                                                         ______________________________________                                        Example    1        2        3     4     5                                    ______________________________________                                        Olefin Source                                                                            Lt FCC   Lt FCC   pygas pygas pygas                                           gasoline gasoline                                                  Vol % Olefin                                                                             50       75       30    30    14                                   Source in blend                                                               Temp, °F.                                                                         800      800      750   800   800                                  Press., psig                                                                             75       75       180   150   190                                  WHSV on feed,                                                                            1.5      1.0      1.0   1.0   1.0                                  hr.sup.-1                                                                     ______________________________________                                    

Material balances on Examples 1-5 were taken at 3 and 8 hours-on-stream.These detailed material balance data are shown in Tables 5-9.

Tables 5-9 show that benzene conversions for Examples 1-5 between 25%and 42% were obtained while producing only a very small amount of C₁₁ +alkyl aromatics, i.e., between 1.5 wt % and 7.5 wt %. A number of cleanfuel benefits other than benzene reduction were also achieved.Reductions of at least 60 weight percent, or between 72% and 81%, forC₅ + olefins and between 0.5 and 1 psi for RVP were obtained. The ratioof C₉ to C₁₀ aromatics is at least 2.5:1. Significant sulfur conversionwas also found, i.e., greater than 60 wt %. The detailed sulfur GCanalysis on the feed and liquid product for MB-1 (three hours on-stream)of Example 2 (Table 10) shows over 70% conversion of both ring(thiophenic) and mercaptan sulfur species. An octane boost is alsoobtained. The magnitude of the uplift depends on the feedstockcomposition and reaction severity.

The use of C₅ + olefin feed as the sole alkylating agent in benzenereduction processes produces novel results as shown in Tables 5-10. Theprior art specifies the use of light olefinic gas feeds (C₂ -C₄olefins). Over ZSM-5, heavy olefins are alkylated to form C₇ -C₁₀aromatics rather than heavier C₁₁ + aromatics. A number of unexpectedclean fuel benefits including sulfur reduction are also obtained. Thesefindings show that MBR effectively converts benzene using heavy olefinsas the alkylating agent and provides added flexibility to the process.This can be especially attractive to refiners with limited light olefinavailability.

                  TABLE 3                                                         ______________________________________                                        Feedstock Properties- Light FCC Naphtha (215-°F.)                      ______________________________________                                        Composition, wt %                                                             Hydrogen           0.0                                                        Methane            0.0                                                        Ethane             0.0                                                        Ethene             0.0                                                        Propane            0.0                                                        Propene            0.0                                                        N-Butane           0.9                                                        Isobutane          0.4                                                        Butenes            3.5                                                        Total C.sub.5 +    95.2                                                       C.sub.5 -C.sub.9 Isoparaffins                                                                    30.1                                                       C.sub.5 -C.sub.9 N-Paraffins                                                                     7.5                                                        C.sub.5 -C.sub.9 Olefins                                                                         44.4                                                       C.sub.5 -C.sub.9 Naphthenes                                                                      7.3                                                        C.sub.6 -C.sub.9 Aromatics                                                                       5.8                                                        C.sub.10 + & unknowns                                                                            0.1                                                        Benzene            2.3                                                        Toluene            3.4                                                        Total Sulfur, ppmw 242                                                        Mercaptan Sulfur, ppmw                                                                           3                                                          Nitrogen, ppmw     7                                                          C.sub.5 + Properties                                                          R + O/M + O        90.4/79.2                                                  Molecular Weight   82.2                                                       Density @ 60° F., g/ml                                                                    0.68                                                       Reid Vapor Pressure, psia                                                                        9.9                                                        ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Feedstock Properties- Pyrolysis Gasoline                                      Composition, wt %                                                             ______________________________________                                        Butenes             1.1                                                       Pentenes            9.9                                                       Pentadienes         2.3                                                       Other C.sub.5       0.9                                                       Benzene             13.1                                                      C.sub.6 Olefins     16.6                                                      Other C.sub.6       0.2                                                       Toluene             6.9                                                       C.sub.7 Olefins     8.6                                                       Other C.sub.7       0.6                                                       C.sub.8 aromatics   3.2                                                       C.sub.8 Olefins     4.8                                                       Other C.sub.8       0.9                                                       C.sub.9 Olefins     6.2                                                       Other C.sub.9       4.3                                                       Other C.sub.10 +    20.5                                                      Total C.sub.9 - Olefins, wt %                                                                     49.5                                                      Total Sulfur, wt %  0.051                                                     Mercaptan Sulfur, ppmw                                                                            129                                                       Nitrogen, ppmw      29                                                        Bromine Number      101.1                                                     Dienes, mmol/g      1.3                                                       R + O               94.4                                                      M + O               77.5                                                      RVP, psia           7.3                                                       ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Example 1: Material Balance Data                                              Feed: 50/50 v/v FCC Lt. Naphtha/Reformate Cut Blend                           ______________________________________                                        Material Balance Number                                                                         Feed     1        2                                         Hours on Stream   --       2        8                                         Reactor Pressure, psig                                                                          --       75       75                                        Avg. Reactor Temperature, °F.                                                            --       800      799                                       Total HC Feed WHSV, hr.sup.-1                                                                   --       1.5      1.5                                       Benzene/C.sub.2 -C.sub.9 Olefins, mol/mol                                                       0.94     0.94     0.94                                      Benzene/C.sub.2 -C.sub.9 Olefins, wt/wt                                                         0.93     0.93     0.93                                      C.sub.2 -C.sub.9 Olefin Conversion, %                                                           --       63.7     50.1                                      C.sub.5 -C.sub.9 Olefin Conversion, %                                                           --       74.6     70.1                                      Benzene Conversion, %                                                                           --       32.3     29.5                                      Composition,                                                                  wt % of hydrocarbon                                                           Hydrogen          0.00     0.01     0.03                                      Methane           0.00     0.02     0.06                                      Ethane            0.00     0.08     0.16                                      Ethene            0.00     0.09     0.33                                      Propane           0.00     2.77     2.93                                      Propene           0.00     0.77     1.60                                      N-Butane          0.24     2.45     2.07                                      Isobutane         0.09     3.33     2.69                                      Butenes           1.00     1.88     2.92                                      Total C.sub.5 +   96.67    88.60    87.21                                     C.sub.5 -C.sub.9 Isoparaffins                                                                   33.81    34.09    33.26                                     C.sub.5 -C.sub.9 N-Paraffins                                                                    13.10    10.50    10.76                                     C.sub.5 -C.sub.9 Olefins                                                                        21.77    5.53     6.51                                      C.sub.5 -C.sub.9 Naphthenes                                                                     5.61     5.22     5.37                                      C.sub.6 -C.sub.9 Aromatics                                                                      24.32    27.00    27.43                                     C.sub.10+  & Unknowns                                                                           0.05     6.25     3.87                                      Benzene           21.18    14.33    14.94                                     Toluene           3.09     4.05     3.88                                      Ethylbenzene      0.02     2.32     2.06                                      Xylenes           0.04     1.02     1.30                                      C.sub.9 Aromatics 0.00     5.28     5.25                                      C.sub.10 Aromatics                                                                              0.01     1.88     1.54                                      C.sub.10 P + O + N                                                                              0.02     0.71     0.77                                      C.sub.11 + & Unknowns                                                                           0.03     3.66     1.56                                      C.sub.5 + Properties                                                          R + O/M + O       86.5/79.0                                                                              89.0/82.8                                                                              88.9/82.1                                 Molecular Weight  83.0     89.4     88.2                                      Density @ 60° F., g/ml                                                                   0.71     0.73     0.73                                      Reid Vapor Pressure, psia                                                                       7.4      6.4      6.5                                       Sulfur, ppmw      125      60.sup.a 78.sup.a                                  ______________________________________                                         .sup.(a) total liquid product                                            

                  TABLE 6                                                         ______________________________________                                        Example 2: Material Balance Data                                              Feed: 75/25 v/v FCC Light Naphtha                                             (215-°F.)/Reformate Cut Blend                                          ______________________________________                                        Material Balance Number                                                                         Feed     1        2                                         Hours on Stream   --       3        9                                         Reactor Pressure, psig                                                                          --       75       75                                        Avg. Reactor Temperature, °F.                                                            --       801      801                                       Total HC Feed WHSV, hr.sup.-1                                                                   --       1.0      1.0                                       Benzene/C.sub.2 -C.sub.9 Olefins, mol/mol                                                       0.42     0.42     0.42                                      Benzene/C.sub.2 -C.sub.9 Olefins, wt/wt                                                         0.41     0.41     0.41                                      C.sub.2 -C.sub.9 Olefin Conversion, %                                                           --       75.5     61.6                                      C.sub.5 -C.sub.9 Olefin Conversion, %                                                           --       86.4     76.8                                      Benzene Conversion, %                                                                           --       43.5     42.6                                      Composition,                                                                  wt % of hydrocarbon                                                           Hydrogen          0.00     0.05     0.04                                      Methane           0.00     0.14     0.10                                      Ethane            0.00     0.36     0.25                                      Ethene            0.00     0.32     0.43                                      Propane           0.00     6.16     4.64                                      Propene           0.00     1.24     1.76                                      N-Butane          0.35     3.86     3.14                                      Isobutane         0.13     5.35     4.25                                      Butenes           1.46     2.22     3.14                                      Total C.sub.5 +   98.05    80.29    82.26                                     C.sub.5 -C.sub.9 Isoparaffins                                                                   32.28    31.41    31.72                                     C.sub.5 -C.sub.9 N-Paraffins                                                                    10.43    7.95     8.59                                      C.sub.5 -C.sub.9 Olefins                                                                        31.48    4.28     7.31                                      C.sub.5 -C.sub.9 Naphthenes                                                                     6.64     5.57     6.07                                      C.sub.6 -C.sub.9 Aromatics                                                                      17.12    25.26    22.90                                     C.sub.10+  & Unknowns                                                                           0.10     5.81     5.68                                      Benzene           13.66    7.72     7.84                                      Toluene           3.40     5.48     5.08                                      Ethylbenzene      0.03     2.67     2.26                                      Xylenes           0.03     3.98     2.56                                      C.sub.9 Aromatics 0.00     5.41     5.16                                      C.sub.10 Aromatics                                                                              0.00     1.55     1.33                                      C.sub.10 P + O + N                                                                              0.04     0.30     0.29                                      C.sub.11 + & Unknowns                                                                           0.06     3.96     4.06                                      C.sub.5 + Properties                                                          R + O/M + O       87.5/79.4                                                                              90.3/82.8                                                                              90.1/82.4                                 Molecular Weight  82.9     90.3     90.1                                      Density @ 60° F., g/ml                                                                   0.70     0.73     0.73                                      Reid Vapor Pressure, psia                                                                       8.3      7.0      7.1                                       Sulfur, ppmw      170      72.sup.a 97.sup.a                                  ______________________________________                                         .sup.(a) total liquid product                                            

                  TABLE 7                                                         ______________________________________                                        Example 3: Material Balance Data                                              Feed: 30/70 v/v Pyrolysis Gasoline/Reformate Cut Blend                        ______________________________________                                        Material Balance Number                                                                           Feed       1                                              Hours on Stream     --         3                                              Reactor Pressure, psig                                                                            --         180                                            Avg. Reactor Temperature, °F.                                                              --         751                                            Total HC Feed WHSV, hr.sup.-1                                                                     --         1.0                                            Benzene/C.sub.2 -C.sub.9 Olefins, mol/mol                                                         3.43       --                                             Benzene/C.sub.2 -C.sub.9 Olefins, wt/wt                                                           3.25       --                                             C.sub.2 -C.sub.9 Olefin Conversion, %                                                             --         73.6                                           C.sub.5 -C.sub.9 Olefin Conversion, %                                                             --         81.1                                           Benzene Conversion, %                                                                             --         33.8                                           Composition, wt % of hydrocarbon                                              Hydrogen            0.00       0.00                                           Methane             0.00       0.02                                           Ethane              0.00       0.09                                           Ethene              0.00       0.03                                           Propane             0.00       3.68                                           Propene             0.00       0.28                                           N-Butane            0.00       2.65                                           Isobutane           0.00       3.05                                           Butenes             0.33       0.71                                           Total C.sub.5 +     99.67      89.48                                          C.sub.5 -C.sub.9 Isoparaffins                                                                     16.42      15.51                                          C.sub.5 -C.sub.9 N-Paraffins                                                                      15.30      9.74                                           C.sub.5 -C.sub.9 Olefins                                                                          12.42      2.35                                           C.sub.5 -C.sub.9 Naphthenes                                                                       4.28       2.71                                           C.sub.6 -C.sub.9 Aromatics                                                                        46.29      47.98                                          C.sub.10+  & Unknowns                                                                             4.96       11.19                                          Benzene             41.42      27.44                                          Toluene             3.08       4.39                                           Ethylbenzene        0.26       3.81                                           Xylenes             0.64       1.71                                           C.sub.9 Aromatics   0.89       10.64                                          C.sub.10 Aromatics  0.72       3.40                                           C.sub.10 P + O + N  0.54       0.44                                           C.sub.11 + & Unknowns                                                                             3.70       7.35                                           C.sub.5 + Properties                                                          R + O/M + O         88.3/77.3  93.9/84.3                                      Molecular Weight    85.7       93.1                                           Density @ 60° F., g/ml                                                                     0.77       0.79                                           Reid Vapor Pressure, psia                                                                         4.9        4.0                                            ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                        Example 4: Material Balance Data                                              Feed: 30/70 v/v Pyrolysis Gasoline/Reformate Cut Blend                        ______________________________________                                        Material Balance Number                                                                         Feed     1        2                                         Hours on Stream   --       3        8                                         Reactor Pressure, psig                                                                          --       150      150                                       Avg. Reactor Temperature, °F.                                                            --       800      800                                       Total HC Feed WHSV, hr.sup.-1                                                                   --       1.0      1.0                                       Benzene/C.sub.2 -C.sub.9 Olefins, mol/mol                                                       3.43     3.43     3.43                                      Benzene/C.sub.2 -C.sub.9 Olefins, wt/wt                                                         3.25     3.25     3.25                                      C.sub.2 -C.sub.9 Olefin Conversion, %                                                           --       65.0     56.1                                      C.sub.5 -C.sub.9 Olefin Conversion, %                                                           --       77.1     74.6                                      Benzene Conversion, %                                                                           --       29.6     24.7                                      Composition,                                                                  wt % of hydrocarbon                                                           Hydrogen          0.00     0.07     0.05                                      Methane           0.00     0.46     0.37                                      Ethane            0.00     0.87     0.87                                      Ethene            0.00     0.11     0.18                                      Propane           0.00     7.09     5.29                                      Propene           0.00     0.47     0.82                                      N-Butane          0.00     2.47     1.70                                      Isobutane         0.00     2.61     1.67                                      Butenes           1.33     1.04     1.45                                      Total C.sub.5 +   99.67    84.81    87.61                                     C.sub.5 -C.sub.9 Isoparaffins                                                                   16.42    12.31    13.97                                     C.sub.5 -C.sub.9 N-Paraffins                                                                    15.30    8.13     9.54                                      C.sub.5 -C.sub.9 Olefins                                                                        12.42    2.84     3.15                                      C.sub.5 -C.sub.9 Naphthenes                                                                     4.28     2.09     2.46                                      C.sub.6 -C.sub.9 Aromatics                                                                      46.29    49.85    50.57                                     C.sub.10+  & Unknowns                                                                           4.96     9.59     7.91                                      Benzene           41.42    29.17    31.19                                     Toluene           3.08     6.58     6.48                                      Ethylbenzene      0.26     5.71     5.29                                      Xylenes           0.64     2.12     1.99                                      C.sub.9 Aromatics 0.89     6.27     5.62                                      C.sub.10 Aromatics                                                                              0.72     2.71     2.09                                      C.sub.10 P + O + N                                                                              0.54     0.26     0.22                                      C.sub.11 + & Unknowns                                                                           3.70     6.62     5.60                                      C.sub.5 + Properties                                                          R + O/M + O       88.3/77.3                                                                              96.2/86.0                                                                              94.7/84.7                                 Molecular Weight  85.7     91.8     90.6                                      Density @ 60° F., g/ml                                                                   0.77     0.80     0.79                                      Reid Vapor Pressure, psia                                                                       4.9      3.9      4.0                                       ______________________________________                                    

                  TABLE 9                                                         ______________________________________                                        Example 5: Material Balance Data                                              Feed: 14/86 v/v Pyrolysis Gasoline/Reformate Cut Blend                        ______________________________________                                        Material Balance Number                                                                         Feed     1        2                                         Hours on Stream   --       3        8                                         Reactor Pressure, psig                                                                          --       190      190                                       Avg. Reactor Temperature, °F.                                                            --       800      799                                       Total HC Feed WHSV, hr.sup.-1                                                                   --       1.0      1.0                                       Benzene/C.sub.2 -C.sub.9 Olefins, mol/mol                                                       2.74     2.74     2.74                                      Benzene/C.sub.2 -C.sub.9 Olefins, wt/wt                                                         2.59     2.59     2.59                                      C.sub.2 -C.sub.9 Olefin Conversion, %                                                           --       57.5     49.8                                      C.sub.5 -C.sub.9 Olefin Conversion, %                                                           --       77.9     76.0                                      Benzene Conversion, %                                                                           --       45.8     42.0                                      Composition,                                                                  wt % of hydrocarbon                                                           Hydrogen          0.00     0.15     0.03                                      Methane           0.00     0.44     0.42                                      Ethane            0.00     1.17     1.16                                      Ethene            0.00     0.20     0.26                                      Propane           0.00     10.57    9.57                                      Propene           0.00     0.57     0.81                                      N-Butane          0.00     3.99     3.76                                      Isobutane         0.00     3.92     3.49                                      Butenes           0.01     1.08     1.31                                      Total C.sub.5 +   99.99    77.90    79.19                                     C.sub.5 -C.sub.9 Isoparaffins                                                                   33.40    23.24    25.10                                     C.sub.5 -C.sub.9 N-Paraffins                                                                    20.92    7.01     8.36                                      C.sub.5 -C.sub.9 Olefins                                                                        9.05     2.00     2.17                                      C.sub. 5 -C.sub.9 Naphthenes                                                                    5.46     1.91     2.11                                      C.sub.6 -C.sub.9 Aromatics                                                                      27.93    35.25    34.49                                     C.sub.10+  & Unknowns                                                                           3.25     8.49     6.96                                      Benzene           23.45    12.71    13.61                                     Toluene           3.10     6.83     6.24                                      Ethylbenzene      0.20     5.81     5.99                                      Xylenes           0.49     4.15     3.47                                      C.sub.9 Aromatics 0.68     5.75     5.18                                      C.sub.10 Aromatics                                                                              0.56     2.34     1.92                                      C.sub.10 P + O + N                                                                              0.33     0.06     0.05                                      C.sub.11 + & Unknowns                                                                           2.36     6.09     4.99                                      C.sub.5 + Properties                                                          R + O/M + O       80.5/74.6                                                                              95.6/85.5                                                                              93.3/85.1                                 Molecular Weight  88.2     95.7     94.3                                      Density @ 60° F., g/ml                                                                   0.73     0.77     0.76                                      Reid Vapor Pressure, psia                                                                       4.8      4.1      4.2                                       Sulfur, ppmw      91       N/A      38.sup.a                                  ______________________________________                                         .sup.(a) total liquid product                                            

                  TABLE 10                                                        ______________________________________                                        Example 2 - Detailed Sulfur GC Results (MB-1)                                 Feed: 75/25 v/v FCC Light Naphtha                                             (215-°F.)/Reformate Cut Blend                                                             Feed TLP                                                   ______________________________________                                        Wt % of Feed         100    84                                                Composition, ppm                                                              Total S              187    75                                                Thiophene (T)        77     15                                                C.sub.1 -T           100    21                                                C.sub.2 -T           3      9                                                 C.sub.3 +T           0      14                                                Total Thiophenes     179    59                                                Benzothiophene (BTH) <1     1                                                 C.sub.1 -BTH         1      3                                                 C.sub.2 +BTH         0      4                                                 Total BTH            1      8                                                 Total H.sub.2 S + Mercaptans                                                                       7      7                                                 Dissolved H.sub.2 S  0      5                                                 C.sub.1 -C.sub.3 Mercaptan                                                                         0      2                                                 Net Conversion, wt %.sup.a                                                    Total S              67                                                       Thiophene            84                                                       C.sub.1 -Thiophene   82                                                       Overall Thiophene    72                                                       ______________________________________                                         .sup.(a) Assumed negligible C.sub.5 + range sulfur in gas product.       

While the invention has been described by reference to specificembodiments there is no intent to limit the scope of the inventionexcept as described in the appended claims.

What is claimed is:
 1. A process for alkylating a benzene-rich gasolineboiling range hydrocarbon feedstream with a hydrocarbon streamcomprising C₅ + olefins to produce product gasoline having a reducedbenzene content and containing aromatics comprising substantiallyentirely C₁₀ - alkylated aromatics, said process comprising:contactingsaid benzene-rich stream and said C₅ + olefin stream in a fluidized bedwith solid, shape selective aluminosilicate catalyst particles in acatalyst bed under benzene alkylation conditions whereby an effluentstream is produced comprising said gasoline having a reduced benzenecontent and in which the aromatics which are present are substantiallyentirely C₁₀ - alkylated aromatics.
 2. The process of claim 1 whereinsaid catalyst comprises acidic ZSM-5.
 3. The process of claim 1 whereinsaid benzene alkylation conditions comprise temperature between 500° F.and 1000° F., pressure between about 50 (350 kPa) and 3000 psig (21000kPa), and liquid hourly space velocity between 0.1 and about
 250. 4. Theprocess of claim 3 wherein said benzene alkylation conditions comprisetemperature 700°-850° F. (371°-454° C.), pressure between 50-400 psig(350-2860 kPa), and liquid hourly space velocity between about 1 and100.
 5. The process of claim 1 wherein said hydrocarbon streamcomprising C₅ + olefins comprises cracked gasoline.
 6. The process ofclaim 5 wherein said cracked gasoline is selected from the groupconsisting of FCC gasoline, TCC gasoline, coker gasoline and pyrolysisgasoline.
 7. The process of claim 1 wherein said product gasoline alsohas a lower Reid vapor pressure than the gasoline boiling rangefeedstream.
 8. The process of claim 1 wherein said product gasoline hasa lower sulfur content relative to said gasoline feedstream.
 9. Theprocess of claim 1 wherein said benzene content is lowered by at least25 weight percent relative to said hydrocarbon feedstream.
 10. A processfor the reduction of the benzene and olefin content of C₅ + FCC gasolinefeedstream containing benzene and C₅ + olefins, said processcomprising:contacting the C₅ + FCC gasoline feedstream with solid, shapeselective aluminosilicate catalyst particles in a fluidized catalyst bedunder benzene alkylation conditions whereby the benzene in thefeedstream is alkylated with the C₅ + olefins of the feedstream toproduce an effluent stream comprising said gasoline having a reducedbenzene and olefin content in which the aromatics which are present aresubstantially entirely C₁₀ - alkylated aromatics.
 11. The process ofclaim 10 wherein at least a 25 weight percent reduction in benzenecontent and at least a 60 weight percent reduction in C₅₊ olefin contentis achieved.
 12. The process of claim 10 wherein said catalyst comprisesZSM-5.
 13. The process of claim 10 wherein said benzene alkylationconditions comprise temperature 700°-850° F. (371°-454° C.), pressurebetween 50-400 psig (350-2860 kPa), and liquid hourly space velocitybetween about 1 and
 100. 14. The process of claim 10 wherein saideffluent stream has a lower Reid vapor pressure than the gasolinefeedstream.
 15. The process of claim 10 wherein said effluent stream hasa lower sulfur content relative to said gasoline feedstream.
 16. In theprocess for reducing the benzene content of a reformate feedstreamcontaining benzene, the process comprising alkylating the reformatefeedstream with olefins in a fluidized bed in contact with shapeselective metallosilicate catalyst particles, the improvementcomprising:alkylating said reformate feedstream with higher olefinscomprising a C₅ + olefin rich feedstream to alkylate the benzene of thereformate feedstream with the C₅ + olefins whereby an effluent stream isproduced comprising said reformate having a reduced benzene content inwhich the aromatics which are present are substantially entirely C₁₀ -alkylated aromatics.
 17. The process of claim 16 wherein said catalystcomprises acidic ZSM-5.
 18. The process of claim 16 wherein saideffluent stream has a lower Reid vapor pressure and lower sulfur contentrelative to said C₅ + feedstream.
 19. The process of claim 16 wherein atleast a 60 weight percent reduction in C₅₊ olefin content of saidreformate feedstream is achieved.
 20. A process for lowering the benzeneand olefin content of a benzene-rich and C₅ + olefin-rich C₅ + gasolinefeedstream comprising:contacting said feedstream with solid, shapeselective aluminosilicate catalyst particles in a fluidized catalyst bedunder benzene alkylation conditions whereby the benzene of thefeedstream is alkylatd with C₅ + olefins of the feedstream to produce aneffluent stream comprising a gasoline feedstream having a reducedbenzene and olefin content relative to the feedstream and in which thearomatics which are present are substantially entirely C₁₀ - alkylatedaromatics.
 21. The process of claim 20 wherein said catalyst comprisesacidic ZSM-5.
 22. The process of claim 20 wherein at least a 25 weightpercent reduction in benzene content and at least a 60 weight percentreduction in C₅₊ olefin content is achieved.
 23. The process of claim 20wherein said benzene alkylation conditions comprise temperature700°-850° F. (371°-454° C.), pressure between 50-400 psig (350-2860kPa), and liquid hourly space velocity between about 1 and 100.